Steam-engine



(No Model.) V 2 Sheets-Sheet 1.

DEURNS'.

STEAM ENGINE. l No. 416,823. Patented-Dec. 10, 1889 i ZL /l E v n q".

(No Model.) 2 Sheets-Syed 2."

D. BURNS.

V STEAM ENGINE. 10.416,823. v1 f.-'e11t.=,(113. 1o, 1889.

N. PETERS Pmmumogmnr. mmmmm u a the middle being for the exhaust-one for in the county of Muskegon and State of Michi- UNITEDv STATES PATENT OFFICE. 1

DAVID BURNS, OF MUSKEGON, MICHIGAN.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 416,823, dated December 10, 1889.

Application filed March 20, 1 889.

T 0 all whom it may concern:

Be 1t known that I, DAVID BURNS, a citizen of the UnitedStates, residing at Muskegon,

gan, have invented certain new 'and useful Improvements in Steam-Engines, of which the following is such a full, clear, and exact description as will enable others skilled in the art to which it appertains vto make and use the same, reference being had to the accompanying drawings, which illustrate the construe.- tion and arrangement of the different parts.

The general features and purposes of" this invention are to furnish a perfect cushion for the piston at both ends of its stroke, which is accomplished by closing the exhaust-port before the piston reaches the end of the cylinder, thus inelosing a portion of the exhauststea1n,whieh is compressed by the continued movement ofthe piston. To produce this result, the cylinder is provided with separate and distinct passages for the transmission of live and exhaust steam from its interior to and from the steam-chest, the passages for live steam terminating in the usual manner in close contiguity with the cylinder-heads, while the exhaust-passages lopen into the interior of the cylinder at a distance of more than the thickness of the piston from said heads. Thus when the piston in its reciprocations reaches said openings they are closed by it and further escape of steam from that end of the cylinder prevented. As the valve which admits steam must be in position to l admit live steam instantly upon the piston reaching the end of its stroke, it becomes neoessary to close the exhaust-opening at the end receiving steam. This is accomplished by the movement of the valve in the steamchest, said valve being provided with four separate and distinct ports, the two nearest each end of the cylinder-and the end ports controlling the admission of live steam. By

this construction of valve and the two separate ports and passages for each end of the cylinder the movements of the valve are made to fully control the admission and exit of steam from said cylinder.

In the drawings, in which similar letters of reference indicate like parts in the diiferent Serial No. 304,005. (No model.)

chest, and valves, showing the relative positions ofthe different parts and passages in the same. Fig. 3 is a vertical transverse section on line :c of Fig. 1. Fig. 4 is a similar section on line 'y y, Fig. 1. Fig. 5 is a plan with the position of the several ports and passages indicated by dotted lines; and Fig. 6 is a section of valve and chest, showing the valve in another position.

In the figures, A represents the steam-cylinder, and B the piston which reciprocates within said cylinder.

ct a represent the passages through the cylinder which conduct live steam from the steam-chest C, and ct a the exhaust-passages, through which the steam makes its exit. As

will be observed, these passages run parallel and are formed in the usual way by cores inserted in the mold when the cylinder is cast.

As heretofore stated, the live-steam passages a c enter the cylinder in close-proximity to the heads A of the same, the exhaust-passages d' a opening at a certain distance, which distan ce may be varied as it is desired to give more or less cushioning to the piston,

as thegreater the distance from the head to and is inclosed within the cylindrical chamber of the steam-chest C, which steam-chest is provided with an opening l, through which live steam enters the chest, and with another opening Zz', through which the exhaust-steam escapes.

The valve D is provided with four encircling grooves, two of which c c form the openings or.ports through which live steam enters the passages ct a, leading to the cylinder, and the grooves c c thbse through which the ex haust-steam escapes to the exit-opening b. With the exception of these grooves turned in its periphery, the valve is a plain cylinder of equal diameter from end to end, having a ICO smooth outer surface that lits snugly the bored chamber of the steamchest from one portor groove to another, but not so tightly as to prevent its ready reciprocation by means of an eccentric and the valve-rod D.

The operation of the mechanism is plainly illustrated in Fig. 2 of the drawings, in which the piston is shown as having passed the eXn haust-opening at one end of the cylinder, and consequently compressing the steam between it and the cylinder-head. The valve is also nearly in position to admit steam to this end for the purpose of reversing' the movement ot' the piston, the exhaust-passage at this end being closed and that at the opposite end of Vthe cylinder opened to allow the escape ot' indcr and the exhaust-port at a distance of about the thickness of the portion from it, in combination with a four-ported circular' valve adapted to close one of the exhaust-passages and prevent the escape of live steam until the piston shall have reached the end of the stroke, substantially as shown and described.

2. As an ilnprovement in steam-cylinders, the combination of a steam-cylinder provided with two exhaust and two steam passages, all ending at different points in the length of said cylinder, with the cylindrical steam-chest and valve having four encircling grooves or ports moving in said steam-chest, all arranged and operating substantially as specied.

In testimony whereof l affix my signature in presence of two witnesses.

DAVID BURNS.

lVitnesses:

THOMAS HUME, MARTIN Down. 

